This invention relates to a stern drive for watercraft and particularly to a gimbal ring steering arrangement for use with a stern drive.
Kiekhaefer, in U.S. Pat. No. 3,136,285, describes a steering arrangement having a gimbal ring with a generally vertical steering swivel shaft rotatably disposed in a transom bracket attached to the transom of a watercraft. The drive unit is pivotally supported by the gimbal ring on a generally transverse horizontal axis to provide tilt movement. In this arrangement the steering swivel shaft is attached to the gimbal ring by a splined connection. Such an arrangement has proven highly satisfactory because it permits a steering arm to be attached to the steering swivel shaft and extend forwardly through the transom mounting opening and into the interior of the watercraft, thereby providing a compact arrangement which allows the steering control means to attach to the steering arm inside the boat. This prior art device fails to achieve full contact between the mating surfaces of the steering swivel shaft and the gimbal ring.
One other prior art device utilized a square bore in the gimbal ring and a complementary steering swivel shaft section to replace the splined joint disclosed by Kiekhaefer. The swivel shaft of this device was split along its axis through the square section and used a screw on the shaft axis to spread the shaft and force it into contact with the gimbal ring. This device failed to achieve contact along the full vertical length of the mating surfaces.